Datasheet LT3579, LT3579-1 (Analog Devices) - 9
| Manufacturer | Analog Devices |
| Description | 6A Boost/Inverting DC/DC Converter with Fault Protection |
| Pages / Page | 42 / 9 — STATE DIAGRAM. Figure 2. State Diagram |
| Revision | B |
| File Format / Size | PDF / 1.1 Mb |
| Document Language | English |
STATE DIAGRAM. Figure 2. State Diagram
Model Line for this Datasheet
Text Version of Document
LT3579/LT3579-1
STATE DIAGRAM
SHDN < 1.33V OR VIN < 2.3V CHIP OFF • ALL SWITCHES DISABLED • IGATE OFF • FAULTS CLEARED SHDN > 1.33V AND VIN > 2.3V INITIALIZE • SS PULLED LOW FAULT1 FAULT2 SS < 50mV FAULT DETECTED • SS CHARGES UP SOFT START • IGATE OFF • FAULT PULLED LOW INTERNALLY BY LT3579 • IGATE ENABLED FAULT1 • SWITCHER DISABLED • SS CHARGES UP • CLKOUT DISABLED • SWITCHER ENABLED SS > 1.8V AND NO FAULT1 CONDITIONS STILL DETECTED POST FAULT DELAY SAMPLE MODE • SS SLOWLY DISCHARGES FAULT1 • Q1 & Q2 SWITCHES FORCED ON EVERY CYCLE FOR AT LEAST MINIMUM FAULT1 ON-TIME SS < 50mV • IGATE FULLY ACTIVATED WHEN SS > 500mV LOCAL FAULT OVER • INTERNAL FAULT PULLDOWN FAULT1 RELEASED BY LT3579 • SS CONTINUES DISCHARGING TO GND IF |VOUT| DROPS CAUSING: FB < 1.17V (BOOST) NORMAL MODE FAULT > 1.0V OR FB > 45mV (INVERTING) • NORMAL OPERATION • CLKOUT ENABLED WHEN FAULT1 SS > 1.8V FAULT1 = OVER VOLTAGE PROTECTION ON VIN (VIN > 16.2V (MIN)) FAULT2 = FAULT PULLED LOW EXTERNALLY (FAULT < 0.75V) OVER TEMPERATURE (TJUNCTION > 165°C (TYP)) OVER CURRENT ON SW1 (ISW1 > 3.4A (MIN)) OVER VOLTAGE PROTECTION ON SW1 (VSW1 > 42V (MIN)) OVER VOLTAGE PROTECTION ON SW1 (VSW2 > 42V (MIN)) 35791 SD
Figure 2. State Diagram
Rev. B For more information www.analog.com 9 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram State Diagram Operation Applications Information Appendix Typical Application Package Description Typical Application Related Parts Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram State Diagram Operation Applications Information Appendix Typical Application Package Description Revision History Typical Application Related Parts
STATE DIAGRAM
SHDN < 1.33V OR VIN < 2.3V CHIP OFF • ALL SWITCHES DISABLED • IGATE OFF • FAULTS CLEARED SHDN > 1.33V AND VIN > 2.3V INITIALIZE • SS PULLED LOW FAULT1 FAULT2 SS < 50mV FAULT DETECTED • SS CHARGES UP SOFT START • IGATE OFF • FAULT PULLED LOW INTERNALLY BY LT3579 • IGATE ENABLED FAULT1 • SWITCHER DISABLED • SS CHARGES UP • CLKOUT DISABLED • SWITCHER ENABLED SS > 1.8V AND NO FAULT1 CONDITIONS STILL DETECTED POST FAULT DELAY SAMPLE MODE • SS SLOWLY DISCHARGES FAULT1 • Q1 & Q2 SWITCHES FORCED ON EVERY CYCLE FOR AT LEAST MINIMUM FAULT1 ON-TIME SS < 50mV • IGATE FULLY ACTIVATED WHEN SS > 500mV LOCAL FAULT OVER • INTERNAL FAULT PULLDOWN FAULT1 RELEASED BY LT3579 • SS CONTINUES DISCHARGING TO GND IF |VOUT| DROPS CAUSING: FB < 1.17V (BOOST) NORMAL MODE FAULT > 1.0V OR FB > 45mV (INVERTING) • NORMAL OPERATION • CLKOUT ENABLED WHEN FAULT1 SS > 1.8V FAULT1 = OVER VOLTAGE PROTECTION ON VIN (VIN > 16.2V (MIN)) FAULT2 = FAULT PULLED LOW EXTERNALLY (FAULT < 0.75V) OVER TEMPERATURE (TJUNCTION > 165°C (TYP)) OVER CURRENT ON SW1 (ISW1 > 3.4A (MIN)) OVER VOLTAGE PROTECTION ON SW1 (VSW1 > 42V (MIN)) OVER VOLTAGE PROTECTION ON SW1 (VSW2 > 42V (MIN)) 35791 SD
Figure 2. State Diagram
Rev. B For more information www.analog.com 9 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram State Diagram Operation Applications Information Appendix Typical Application Package Description Typical Application Related Parts Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram State Diagram Operation Applications Information Appendix Typical Application Package Description Revision History Typical Application Related Parts
